Treatment of flue-dust.



J. 1. SOUTHBR'. TREATMENT 0E' FLUE DUST APPLICATION FILED MAY 15, 1905.

Patented Oct. 15

' INlfuNTo/e.

Application filed May-15, 1905. Serial No. 260,462.

rar

ganar 'erica TREATMENT 0F BLUE-DUST.

To all whom 'it may concern:

Be it known that I, JOHN I. SOUTHER, a citizen ofthe United States, residing in the borough of lestmont, in the county of 'Cambria' and State of Pennsylvania, have invented certain new and useful Improvements in t-he Treatment of Flue-Dust; and

I do herebydeclare the follow-ing to be a full', clear, and exact description of the invention, such as will enable others skilled in the art to Which it appertains to make and use the same.

In conducting metallurgical operations re' quiring the smelting or other treat-ment of understood. This deposit of line ores is or# dinar-ily called flue-dust, and in order to simplify the phraseology of this specification, I will confine my description herein to the Hue-dust Which accumulates in connection lwith the operation of a blast furnace smelting iro-n ore, although it will be understood that my treatment Will apply equally well to flue-dust obtained from any other sources, or to. fine ores of any kind or derivay tion. In-order to simplify the language of the specification by using uniform expressions herein, I employ the term ftflue-dust as applying to anyone of the inely divided ,materials which may be treated by my method, as will be readily understood by one skilled in this art. Under certain conditions, as heretofore explained, the amount of fluedust which accumulates is very considerable, but if it is re-charged into the furnace in the attempt to smelt it, most of it is blown out again by the force of the blast, thus resulting in labor and expense without compensation.

My invention consists briefly in ,treating 'flue-dust by agglomerating or sintering it into rough lumpy form by means of high heat applied thereto, preferably in a revolving cylindrical furnace', using blast fun 'nace gas as'afuel. yIn order tohave this matter clearly understood, I have illustrated Specification of Letters Patent.

Patented oet. 15,1912'.

on the accompanying sheet of drawings, one form of apparatus which may be used for this purpose.

Referring to the accompanying sheet of drawings z-Figure l is a side elevation of a revolving cylinder showing the combustion chamber and stack in longitudinal section. Fig. 2 is a cross section taken on the line 2-2 of Fig. l and 'also showing a car i1rposition to receive the material after it has received my treatment.

Referring now to the .various characters of reference on the drawings :Hl represents a revoluble cylinder lined in its interior with. refractory and preferably basic material, 2 indicates the driving mechanism for revolving same by means of a motor (not shown), 3 isV the combustion chamber-,in which the heating gases are brought into contact with the air and allowed to expand and reverberate for the purpose of obtaining a high heat in the lower end of the inby means of the inclined chute as shown,

and 9 are lumps of flue-dust formed from the fine 'material as it is passed through the heated cylinder and becomes sintered or agglomeratedinto irregular hard lumps or masses. l

10 is a delivery passage or chute formed in the rear portion of the combustion chamber for conveying the lumps vto any convenient receptacle such as the car indicated at ll, and l2 represents a slide door or damper for regulating the supply of'gas to the combustionchamber.

In carrying out my treatment of lluedust, it is charged into one end of the slowly revolving internally liredrcylinder and it gradually travels toward the lower end thereof, it' becomes heated more and more and thereby sint-ered or partially fused into irregular hard lumps or masses; this action being facilitated by the revolution of the cylinder as may be understood. I t will thus be seen that ymy treatment transforms' the finely divided material, which would be carl 55 treating attheQtime ried away by the blast of a furnace, into solid lumps of substantial'size, which 'can be charged into a furnace and smelted without loss, and although my treatment is a very 5 simple 'and inexpensive one, therein resides a large partof vits value.

I prefer to use waste gasesfrom a blast furnace 'for heating the cylinder, as when burned in'connection with a sii'itable supply of air in a combustion chamber, as indicated on t-he'drawing attached hereto, this wastev gas will furnish a high degree of heat'suiiicient to accomplish the purpose/intnded, and as these gases are practically waste products, the cost of fuel in connection ,with the operation is inconsiderable.v

It -will be noted that the finely divided Hue-dust is charged into the upper end of then revolving and internally heated cylinder, this end being the one nearest the stack and y count of the length of the cylinder, the upper end is of a comparatively low temperature, which however, increases gradually toward the lower or lire end, at which point it should preferably be white hot or of a temperature sufficientA to sinter or clinker the'material treated.

Although I .do not limit myselfto any exact composition of flue-dust for myctreatment, I canl state that I have treated with success the flue-dust collected from an iron blast furnace which contains substantially the following ingredients` viz :-metallic iron (contained infoxids) 57 per cent., silica and alumina 11 per cent., lime .2 per cent., coke and-'loss on ignition 8 per cent., sulfur,

v,L/lihospho'rus and magnesia together, part of l per cent. 40 he temperature of fusion or agglomeration vof fine ores or flue-dust is variable to a certain extent, dependingy upon thedifferent characters of same'and also varies with the rdiiferent vproportions of impurities which vthey contain', such as sulfur, silica, alumina or silicates of alumina and other ingredients. In the'rconduct of -my process, I therefore arrange theA temperature in different parts of the furnace suchl that the upper portion Vis-comparatively cool, with gradually increasing temperature, in said lower portion at the proper degree for partly fusing, agglomerating or sintering the particular kind of ore. or flue-dust which I may be It can. be readily understood l that' a ytemperature which would cause one' ore to fuse completely' and melt wouldonlypartially. fuse or sinter another ore and I therefore am careful to maintain such a degree in the lower end of my apparatus that the material will be agglomerated 'farthest removed from'the fire, and on ac-4 into masses or lumps, and not entirely what I claim and desire to secure by United States Letters Patent is: l. The method of treating finely divided flue-dust whichv consists in charging the same into the upper end of an inclined revolving cylinder, heating the interior of said cylinder by means of blast furnace gas, the

linitial combustion of which is 'accomplished in a combustion chamber connected with the interior and lower end of said cylinder,

'near the lower endthereof, subjectingsaid flue-dust to gradually increasing' temperature, as it travels'towardthe i'ire end of the cylinder, and thereby sintering or agglomv erating the said flue-dust in masses or lumps,

substantially as described.

2. The method of treating finely diyided flue-dust or line-ores which consists' iii charging the same into the upper end of an inclined revolving cylinder, heating the interior -of said cylinderA by means of a mixture 'of combustible gas and air, the initial combustion of which is accomplished in an expansive combustion chamber connected with the lower end of the interior of said cylinder,- whereby the ycombustion of said gases is partially perfected without said cylinder and the highest. temperature attained near the lower end of thecylinder aforesaid, sub]ecting said flue-dust or tine-ores to gradually increasing temperature as they travel toward'the fire end` of the cylinder,

and thereby sintering orl agglomerating the same into masses or lumps by the combined action of the gradually increasing temperature and rolling action.

- 3. The processof agglomerating fine-oresu or residues, which consists in initially burn# ing a mixture of combustible gas. and air out of the presence of said ores or residues and under such lconditions that the result ,ing reaction-gases may expand andl thoroughly mix and then passing the intensely hot products thereof overl the ore or residue to be agglomerated and progressively heating it to a tempera-ture sufficient to partially fuse the impurities therein and cause them tol `become semi-plastic and sticky, and agitating the senii-plastic'massto cause to form into lumps.

In testimony whereofI hereto aflix my signature in the presence of two lwitnesses.

l JOHN I. SOUTHER. lVitnesses:

ELMER Siiavn, Giras. NQ CHAMBERS.

"Copies' et this patent vmay be obtained ,for five `cents each,by addressing the Commissioner of Patents.

Washington, D. C. 

